Field of the Invention
The present invention relates to wireless communications, and more specifically, to a method and apparatus for acquiring information on an access point (AP) in a wireless communication system.
Related Art
With the recent trend of increasing high-rate data traffic, fifth generation mobile communication technologies are in discussion for their realistic and efficient backup. One of requirements for fifth generation mobile communication technologies is the interworking between heterogeneous wireless communication systems, particularly between a cellular system and a wireless LAN (WLAN) system. The cellular system may be one of a 3rd generation partnership project (3GPP) long-term evolution (LTE) system, a 3GPP LTE-A (advanced) system, and an institute of electrical and electronics engineers (IEEE) 802.16 (WiMax, WiBro) system. The WLAN system may be an IEEE 802.11 (Wi-Fi) system. In particular, WLAN is a wireless communication system that is commonly used for various user equipments, and thus, the cellular-WLAN interoperation is a high-priority convergence technique. Offloading by the cellular-WLAN interoperation may increase the coverage and capacity of the cellular system.
The arrival of the ubiquitous environment led to a sharp increase in demand for seamless services anytime, anywhere. The fifth generation mobile communication system may adopt a plurality of radio access technologies (RATs) for always gaining easy access and maintaining efficient performance in any place. In other words, the fifth-generation mobile communication system may use multiple RATs in a converging manner through the interoperation between heterogeneous wireless communication systems. Each entity in the plurality of RATs constituting a fifth-generation mobile communication system may exchange information therebetween, and accordingly, the optimal communication system may be provided to a user in the fifth-generation mobile communication system. Among the plurality of RATs constituting the fifth-generation mobile communication system, a specific RAT may operate as a primary RAT system, and another specific RAT may operate as a secondary RAT system. That is, the primary RAT system may mainly play a role to provide a communication system to a user in the fifth-generation mobile communication system, while the secondary RAT system may assist the primary RAT system. In general, a 3GPP LTE(-A) or IEEE 802.16 cellular system with relatively broad coverage may be a primary RAT system, and a Wi-Fi system with relatively narrower coverage may be a secondary RAT system.
In a fifth-generation mobile communication system constituted of a plurality of RATs, a primary RAT system needs to grasp the entities of a secondary RAT system that operates within its own coverage. For example, in case that a primary RAT system is a cellular system, and a secondary RAT system is a Wi-Fi system, a cellular node such as an eNodeB (eNB), mobility management entity (MME), or new cellular entity need be aware of which access points (APs) are in step within its coverage. An entity of a secondary RAT system may report information on the entity of the second RAT system to a management device (for example, a management server). An AP information management entity in the cellular system, e.g., eNB, MME, or new entity, may acquire information on APs within an area, which is managed by AP information management entity, from a separate management server. For example, if the AP information management entity is the eNB, the eNB may acquire information on APs within its coverage.
When an AP information management server is located outside of a cellular network, there is a need for a method for acquiring, by an AP information management entity in the cellular network, information on APs from the AP information management server through an interface outside of the cellular network.